Sound bar in a box . . . can't understand dialog.

I'd be surprised if the Vizio had passive radiators only because they are typically more expensive to produce but I could be wrong, I'm not very familiar with the brand. The only thing I can think would be to put some type of damping material behind the soundbar...like a dark rolled up soft blanket or pillows or something to absorb sound that is bouncing around in the cabinet. Sometimes putting a speaker in a place like that is going to give you that tunnel sound. How much space is around the edges of the speaker and behind it? 

So I did a quick check and no ports, at least not available to mess with (could be under the glued on fabric).

However, I pulled the soundbar out of where it sits inside the armoire (box) and set it about a foot in front of the armoire on a stool.  Dialog seemed more distinct. So one solution for watching movies is to build a way to do that simply, perhaps a fold/slide out shelf.  We're not heavy TV watchers so that's not a major suck.  Just got to be able to make it invisible when not in use. 

The other alternative, I suppose, is to find some small speakers to hang on the front doors so when they open, they swing outside the box. I do have a pair of small B&Ws that are not in use. Then the issue is no center speaker . . . hummmmm.

If your Visio has an HDMI ARC outlet and your TV has one as well, try that. I had the same problem as you with dialog (but for different reasons) and going from optical to HDMI solved the problem. In fact, everything sounds better.

All the best,
Nonoise

ifmywordsdidglow
Guess you’ll just have to be surprised and wrong. I know for a fact my Vizio has passive radiators. It’s a 2.0 soundbar having 2 - 2 3/4 in drivers and 2 passive radiators. I doubt the owner’s manual is wrong.

Dan
If the dialog is distant, that may be the way you have it adjusted. I also think hanging speakers on the doors is a bad idea. As I previously said, it’s best to minimize contact with the cabinet. Center speaker? Does your soundbar have a center speaker? Can you provide a model number of your soundbar or what is it's width? If 28-32 inches, no center speaker.

tls49
Thanks. I’ll ck the model number in the morning. I suspect there’s no center speaker since it was sort of bottom of the line. The free standing approach I tried worked somewhat but would be a pain to set up each use. The next rainy day I’m going to try hanging the extra speakers for the heck of it. My reasoning is that this “box” is extremely heavy, ancient hardwood and not very resonate itself. I think the issue may be reflections inside. 

Everybody
All the suggestions got my brain going, thanks! Time to experiment...which is half the fun😊